CVE-2026-7886

MEDIUMNVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 79% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
4.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Concrete CMS 9.5.0 and below is vulnerable to IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The AddMessage and UpdateMessage conversation controllers accept user-supplied file attachment IDs and load files directly via $em->find(File::class, $attachmentID) without checking per-file permissions (canViewFile()). A user who can post in any conversation can reference any file in the CMS file manager by its sequential ID, effectively bypassing the file permission system.  The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with a vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Tristan Mandani for reporting. if a site truly has private files, the owner should set up a private storage location https://documentation.concretecms.org/user-guide/editors-reference/dashboard/system-and-maintenance/files/file-storage-locations outside of the webroot so that permissions can be checked on view as well. That way, even if a authorized user attaches a file, or otherwise links to it, unauthorized users won't be able to view the file.

CVSS v3
4.3
EG Score
4.3(medium)
EG Risk
19(Track)
EG Risk 19/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
20.9%
KEV
Not listed

Published

May 21, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Jun 27, 2026
No patch confirmed yet.
generic

9.5.1 Release Notes :: Concrete CMS

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes

Vendor Advisories for CVE-2026-7886(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
concrete5/concrete58.0 ... 9.5.0RC2 (89 versions)9.5.1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-24 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:23 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-21 15:25 UTCEPSS rescore
  6. 2026-07-21 15:25 UTCEPSS rescore
  7. 2026-07-20 17:08 UTCEPSS rescore
  8. 2026-07-19 14:31 UTCEPSS rescore
  9. 2026-07-19 02:29 UTCEPSS rescore
  10. 2026-07-18 10:04 UTCEPSS rescore
  11. 2026-07-17 21:59 UTCOSV refresh
  12. 2026-07-16 17:03 UTCEPSS rescore
  13. 2026-07-15 16:57 UTCEPSS rescore
  14. 2026-07-15 02:00 UTCEPSS rescore
  15. 2026-07-13 22:31 UTCEPSS rescore
  16. 2026-07-13 06:13 UTCEPSS rescore
  17. 2026-07-12 05:46 UTCEPSS rescore
  18. 2026-07-11 08:27 UTCEPSS rescore
  19. 2026-07-09 19:10 UTCEPSS rescore
  20. 2026-07-09 19:10 UTCEPSS rescore
  21. 2026-07-08 15:16 UTCEPSS rescore
  22. 2026-07-08 15:16 UTCEPSS rescore
  23. 2026-07-07 13:46 UTCEPSS rescore
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-06 16:27 UTCEPSS rescore
Show 67 more
  1. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 02:23 UTCEPSS rescore
  3. 2026-07-06 02:23 UTCEPSS rescore
  4. 2026-07-05 02:31 UTCEPSS rescore
  5. 2026-07-05 02:30 UTCEPSS rescore
  6. 2026-07-01 15:07 UTCEPSS rescore
  7. 2026-06-30 23:22 UTCEPSS rescore
  8. 2026-06-29 14:06 UTCEPSS rescore
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-27 03:08 UTCEPSS rescore
  12. 2026-06-25 13:50 UTCEPSS rescore
  13. 2026-06-24 14:05 UTCEPSS rescore
  14. 2026-06-23 21:33 UTCEPSS rescore
  15. 2026-06-22 14:25 UTCEPSS rescore
  16. 2026-06-21 14:56 UTCEPSS rescore
  17. 2026-06-21 01:59 UTCEPSS rescore
  18. 2026-06-19 19:26 UTCEPSS rescore
  19. 2026-06-18 17:52 UTCEPSS rescore
  20. 2026-06-17 19:56 UTCGHSA enrichment
  21. 2026-06-17 17:53 UTCEPSS rescore
  22. 2026-06-16 21:03 UTCGHSA enrichment
  23. 2026-06-16 17:53 UTCEPSS rescore
  24. 2026-06-15 22:46 UTCGHSA enrichment
  25. 2026-06-15 17:49 UTCEPSS rescore
  26. 2026-06-15 17:49 UTCEPSS rescore
  27. 2026-06-14 23:57 UTCGHSA enrichment
  28. 2026-06-14 23:18 UTCEPSS rescore
  29. 2026-06-14 01:45 UTCGHSA enrichment
  30. 2026-06-13 23:00 UTCEPSS rescore
  31. 2026-06-13 03:24 UTCGHSA enrichment
  32. 2026-06-12 23:12 UTCEPSS rescore
  33. 2026-06-12 23:12 UTCEPSS rescore
  34. 2026-06-12 05:07 UTCGHSA enrichment
  35. 2026-06-11 14:00 UTCEPSS rescore
  36. 2026-06-11 06:55 UTCGHSA enrichment
  37. 2026-06-10 22:19 UTCEPSS rescore
  38. 2026-06-10 13:22 UTCEPSS rescore
  39. 2026-06-10 08:44 UTCGHSA enrichment
  40. 2026-06-09 10:32 UTCGHSA enrichment
  41. 2026-06-08 14:17 UTCEPSS rescore
  42. 2026-06-08 12:20 UTCGHSA enrichment
  43. 2026-06-07 15:25 UTCEPSS rescore
  44. 2026-06-07 14:08 UTCGHSA enrichment
  45. 2026-06-06 15:48 UTCGHSA enrichment
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-05 22:47 UTCEPSS rescore
  48. 2026-06-05 17:36 UTCGHSA enrichment
  49. 2026-06-05 06:10 UTCEPSS rescore
  50. 2026-06-04 19:23 UTCGHSA enrichment
  51. 2026-06-04 13:12 UTCEPSS rescore
  52. 2026-06-03 21:11 UTCGHSA enrichment
  53. 2026-06-02 22:59 UTCGHSA enrichment
  54. 2026-06-02 20:13 UTCEPSS rescore
  55. 2026-06-02 00:47 UTCGHSA enrichment
  56. 2026-06-01 13:52 UTCEPSS rescore
  57. 2026-06-01 02:35 UTCEG score recompute▲ 2.00
  58. 2026-06-01 02:35 UTCGHSA enrichment
  59. 2026-05-31 22:30 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-29 13:44 UTCEPSS rescore
  62. 2026-05-28 13:44 UTCEPSS rescore
  63. 2026-05-27 13:40 UTCEPSS rescore
  64. 2026-05-27 13:40 UTCEPSS rescore
  65. 2026-05-26 13:44 UTCEPSS rescore
  66. 2026-05-26 07:18 UTCEPSS rescore
  67. 2026-05-21 22:44 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-7886?
CVE-2026-7886 is a medium vulnerability published on May 21, 2026. Concrete CMS 9.5.0 and below is vulnerable to IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The AddMessage and UpdateMessage conversation controllers accept user-supplied file attachment IDs and load files directly via $em->find(File::class,…
When was CVE-2026-7886 disclosed?
CVE-2026-7886 was first published in the National Vulnerability Database on May 21, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-7886 actively exploited?
CVE-2026-7886 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-7886?
CVE-2026-7886 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-7886?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-7886, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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